25 lines
615 B
Markdown
25 lines
615 B
Markdown
---
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title: Map object keys
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tags: object
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cover: rocky-mountains-2
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firstSeen: 2018-01-11T20:33:14+02:00
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lastUpdated: 2020-10-21T21:54:53+03:00
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---
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Maps the keys of an object using the provided function, generating a new object.
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- Use `Object.keys()` to iterate over the object's keys.
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- Use `Array.prototype.reduce()` to create a new object with the same values and mapped keys using `fn`.
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```js
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const mapKeys = (obj, fn) =>
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Object.keys(obj).reduce((acc, k) => {
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acc[fn(obj[k], k, obj)] = obj[k];
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return acc;
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}, {});
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```
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```js
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mapKeys({ a: 1, b: 2 }, (val, key) => key + val); // { a1: 1, b2: 2 }
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```
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